ugurhan/iStock(WASHINGTON) — The National Air Traffic Controllers Association is suing the Trump administration on behalf of the thousands of members of their union that have not been paid during the protracted shutdown showdown over border wall funding between the president and congressional Democrats.

The suit, filed in federal court in Washington, D.C., claims the administration deprived workers of wages without due process and violated fair labor regulations by not at least paying minimum wage to air traffic controllers and others who are exempted from furlough during the government shutdown. The suit also claims the FAA didn’t promptly pay overtime to union members, an oversight the union says is also in violation of regulations.

The shutdown is hitting U.S. air traffic controllers particularly hard because their numbers are already at a 30-year low, according to NATCA. The number of fully certified ATCs, as they’re called, is 10,500 — the union would ideally like to have 2,000 more. And approximately 2,000 ATCs are scheduled to retire this year.

The mandatory retirement age for ATCs is 56.

More than 200 people were in Washington, D.C. on Thursday afternoon attending a rally organized by the National Air Traffic Controllers Association and leaders from the aviation community over the issue.

The aviation stakeholders had a clear message to deliver: every day the shutdown continues it further disrupts the aviation system and they are demanding that the shutdown end. Leaders from the Air Line Pilots Association, the Association of Flight Attendants, Airlines For America (A4A) and other organizations detailed how the shutdown is negatively affecting segments of the National Airspace System.

“It is an unconscionable thing to think that in a profession like ours where safety in the skies is of the utmost important utmost importance that we would not get paid,” Jim Marinitti said during Thursday’s rally. “I truly don’t know if the people who have the authority to stop this shutdown understand the consequences of the decisions they’re currently making.”